A Selective Cell Population from Dermis Strengthens Bone Regeneration

: Finding appropriate seed cells for bone tissue engineering remains a significant challenge. Considering that skin is the largest organ, we hypothesized that human bone morphogenetic protein receptor type IB (BmprIB)+ dermal cells could have enhanced osteogenic capacity in the healing of critical-sized calvarial defects in an immunodeficient mouse model. In this study, immunohistochemical staining revealed that BmprIB was expressed throughout reticular dermal cells; the positive expression rate of BmprIB was 3.5% ± 0.4% in freshly separated dermal cells, by flow cytometry. Furthermore, in vitro osteogenic capacity of BmprIB+ cells was confirmed by osteogenic-related staining and marker gene expression compared with unsorted dermal cells. In vivo osteogenic capacity was demonstrated by implantation of human BmprIB+ cell/coral constructs in the treatment of 4-mm diameter calvarial defects in an immunodeficient mouse model compared with implantation of unsorted cell/coral constructs and coral scaffold alone. These results indicate that the selective cell population BmprIB from human dermis is a promising osteogenic progenitor cell that can be a large-quantity and high-quality cell source for bone tissue engineering and regeneration. SIGNIFICANCE Dermal cells are a promising cell population for bone regeneration; unfortunately, the osteogenic potential of unsorted cells was quite low. This study demonstrated that a specific cell population in human dermis-bone morphogenetic protein receptor IB (BmprIB)+ cells-exhibited significantly higher osteogenic potential than unsorted dermal cells by repairing critical-sized calvarial defects in an immunodeficient mouse model. This animal study is an extension of a previous in vitro finding in which BmprIB was proven as a marker for enrichment of osteogenic precursor-like cells in human dermis, indicating that the selective cell population BmprIB from human dermis is a promising osteogenic progenitor cell that can provide a large-quantity and high-quality cell source for bone tissue engineering.